Sagina nodosa
Knotted Pearlwort ( Sagina nodosa ), illustration
The Gnarled Pearlwort ( Sagina nodosa ) is a species of the carnation family ( Caryophyllaceae ). This type is similar to the low- lying Pearlwort but is slightly larger and has few flowers in the axils of the upper leaves. Also, it has always five sepals and petals.
- 2.1 hazard
- 4.1 Notes and references
- 4.2 External links
Description
Vegetative characteristics
The Gnarled Pearlwort is an evergreen, perennial, herbaceous plant, reaching heights of growth 5-15 centimeters. She is bald or hairy fluffy, growing prostrate or ascending and little branched. The plant forms a taproot. From the axils not sprout flowering rosettes, they can fall off and take root at appropriate places, so the plant has partly grassy. The constant against stem leaves are narrowly linear, down 5 to 15 mm and above usually less than 5 mm long. You have a short slightly fleshy spike tip.
Inflorescences, flowers and fruits
The flowers are arranged in a loose inflorescence on thin stems that arise from the leaf axils. The five petals have a diameter of 6 to 12 mm. They have a double perianth of five sepals and petals. The entire, white, egg-shaped petals are about twice as long as 2 to 3 mm long sepals. The flower contains ten stamens and a fivefold stylus.
The almost spherical capsule fruit dominates the sepals slightly and opens with five blunt flaps. The small dark brown, egg-shaped seeds are about 0.5 millimeters long.
Occurrence and ecology
The low- lying Pearlwort is circumpolar eurasia matic Florenelement the temperate zones. In the northern regions of Europe and North America, particularly in coastal areas, it is common, also it was partially abducted in southern areas. It located generally at altitudes of about 700 meters, but there are in Switzerland sites at altitudes of 1300 meters.
The Gnarled Pearlwort grows earthy vacancies on moist to wet, nitrogen-rich, mostly calcareous sand, peat or clay soils. Easy salinated soils, with a chloride content of less than 0.3 %, the Gnarled Pearlwort can also endure. It usually occurs in small to large groups. It settled on ( cattle ) occurs damaged areas, on open road and grave edges and in nutrient-poor bogs and bog forests. On the North it grows on meadows and shallow sandy beach back.
Although the flowers are very small, they still produce nectar by glands at the base of the stamens, so that an insect pollination takes place mainly by bees and small flies. However, the hermaphrodite flowers can self-pollinate. The further distribution of the species occurs by seeds that drifted the wind and on the other by vegetative propagation, in which the fallen leaf sprouts take root itself. Overall, however, the species is competitive weak, as they often do not come to the flower or not fully ripen the seeds.
The chromosome number is n = 10 to 12.28
Endangering
The Gnarled Pearlwort is classified as " critically endangered " in Germany. In some states, it is already " threatened with extinction " or even " extinct " as performed as. The portfolio development is declining both in Germany and in Central Europe. In Switzerland, there is implemented in the "Red List " of threatened species. However, it is within Central Europe is still considered safely.
System
The Gnarled Pearlwort bears the botanical name Sagina nodosa (L.) Fenzl. A synonym is Spergula nodosa L. - Sp Pl
It will contain the following sub- types at the moment:
- Sagina nodosa subsp. nodosa is more hairy, especially on the midribs of leaves. Bloom time is late summer. The chromosome number is 2n = 56 It is found in moist columns of rocks along the sea coast and on wet sand in estuaries in heights up to 300 meters. The main distribution area is north-east Canada.
- Sagina nodosa subsp. borealis is distributed across Canada to Greenland. Bloom time is late summer. This subspecies is largely hairless and is spread along the coast and the shores of the Great Lakes. The chromosome number is 2n = 56
Sources and further information
The article is mainly based on the following documents: